For a self-excited power generator system that generates AC (alternating current) output power, when a load thereof suddenly increases, a voltage amplitude of the AC output power drops due to insufficiency of the AC output power, and requires a relatively long time to recover to a value immediately before the drop. A conventional generator exciter device can be used in the self-excited power generator system to reduce the drop and the recovery time. The conventional generator exciter device can provide power to a voltage regulator of the self-excited power generator system, so the voltage regulator can provide more power to excite a field winding of the self-excited power generator system. However, without modification, the conventional generator exciter device can only be used with a few types of voltage regulators.